Transformer-coil insulation.



8 0 9 1 0m 2 nm P A D E T M T A P E E T. A M R TRANSFORMER COIL INSULATION.

APPLICATION FILED DEO.16,1905.

2 SHEETS-SHEET 2 WITNESS-ES ATTORNEY proved conclusive UNITED STATES PATENT OFFICE.

JESSE E. MA'IEER, OF WILKINSBUEG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELEC- TRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TRANSFORMER-COIL INSULATION.

To all whom/it may concern:

Be it known that I, Jnssn MATEER, a citizen of the United States, of Wilkinsburg' in the county of Allegheny and Statev of Pennsylvania, have invented a new and useful Im rovement in Transformer Coil Insulation, 0 which the following is a specification. I

My invention relates to the insulation of coils for electrical apparatus and particularly to means for insu ating and stiflening the coils of alternating electric current trans formers which are adapted for relatively hi h voltage service.

he object of my invention is to provide means for insulatin and stifiening transformer coils that sha 1 be simple and durable in construction and effective in maintaining suitable ventilation, and the parts of which may be separated from the coils and from each other without mutilation or injury. It is specially desirable, in transformers of large'size and high voltage, to provide a coil insulation which may be easily applied andmay stiffen as well as suitably insulate the coil. In order to accomplish this result and provide adequate insulation as well as obviate the tendency for the insulation to separate itselffrom the coil at one part when it is held in close enga enient at another, I em loy a plurality of c annels, angle strips an spacing strips, together with flat barrierplates all of which are preferably constructed of hard insulating material, such as fullerboard. These members are ,so assembled, one part overlap ing another, that an inclosing casing isormedwhich is forced together telescopically when pressure is applied toilahe completely insulated coil or groups of 001 s. r

In the prior art, when coils of electrical apparatus were damaged or when it was necessary to remove the insulating wrapping, for any reason, the removed material was injured to such an extent that it could not be again used for the same purpose. On the other hand, a telescoping casing constructed in the aforesaid manner may readily be takenapart and reassembled for insulating the same or another group of coils.

As the result 0 large numbers of tests and experiments in regard to the insulating prop erties of fluids, sucp as air and oil,it has been Specification of Letters Patent. Application filed December 16,

- obtained which shows Patented April 28, 1908.

1905. Serial No. 292,104.

Volta the distance of separation between currentand a resident carryingpa-rts of unlike potential increases.

In plotting the distance of separation in a fluid such as oil, as a function of the voltage at which a break-down occurs, a curve is that the value of voltags is proportional to the distance of sep aration for relatively low voltages, but a knee in the curve indicates the maximum distance in the fluid for which the ratio is maintained approximately constant, and after this point is reached, the distance increases very rapidly and out of all proportion to-the voltage increase. It has been discovered, however, that the ratio-may be substantially maintained for high voltages if barrier-plates of hard insulating material having a specific inductive capacity approxia front elevation mately the same as that of the fluid are interposed at frequentintervals in the fluid between oints of different potential. The barrier-p ates may be separatedby strips of similar material and the construction in addition to withstanding specially high voltage strains for a given distance, permits of ventilation of the current-carrying parts and the circulation of the fluid.

' My invention is well adapted for the insulation of the high tension coils of relatively large transformers, the construction and insulation of which have involved, in the prior art, a relatively large amount of labor and the use of large quantities of flexible material which materially interfered with'the coil ventilation.

Figure 1 of the accompanying drawings is of a transformer, a portion of the core being removed to disclose the coils, and Fig. -on line II-II of Fig. 1, of a group of trans- \IOIIHGI coils which are provided with the iny that thejresistanee to' 11.

sulation of my inventlon.

Referring to the drawings, a shell type transformer 1 is provided with an inclosing tank or casing 2 and comprises amagnetizable core or shell 3 and a groupl of which are supported from a ollow base 4. The relativeposition of the coils is maintained independently of the core by a coil support 6. The group of magnetizing coils comprises high voltage coils 7 and 8 and aplurality of group-n of low volta e co ls 9, 10' and The 'higli'voltage co' and 8 are estrains does not increase directly as;

2 is an enlarged cross-section,

of coils both sides ol the coils, so that open s formed of insulated conductors 12 and the complete coils are insulated by a plurality of spacing strips 13, which are located near the edges of the assembled COllS, and intermediate strips 14 which are bound against the side of the coil and parallel to the strips 13. Channel pieces 15 are next fitted over the edges of the coils and over the spacing strips 13 and serve to protect the coils from mechanical injury well as to give additional insulation.

An insulating plate or barrier between the coils 7 and S, and the channel pieces 15 and the spacing strips 14 keep the insulating plate out of engagement with the aces are left uid, such as Angle strips 17 16 is located through which an insulating oil or air, may circulate. are placed outside of the assembled group over the corners of the channel pieces 15 and the plane surfaces of one angle strip overlap those of the next preceding strip on the adjacent corner of the assembled coil in such a way as to form a telescopic inclosing casing, the sides of the casing being completed by alternate barrier-plates 18, which are similar to the plate 16, and spacing strips 19 which are placed alongside the strips 14. The rigidity of the insulating material of which the angle strips and the barriers are constructed materially stillens the coils, and the telescopic corner arrangement causes the insulating box to slideto ether and form a solid mass of minimum vo nine, when pressure is applied to the insulatedcoil, without interfering with the ventilation of the coil which is maintained by thespacing strips.

Groups of low erably insulated in a similar manner to a less de ree are assembled on each side of the high vo tage group and are separated therefrom by a plurality of barrier-plates 20. After the insulation for the high tension coils has been forced into as small a space as possible, the assembled coils are bound together: by strips of any suitable material and are then in condition to be finally assembled with their inagnetizable'core, being well protected from mechanical irjury and distortion i rcason'oi the hardness of the insulating ma terial.

Although I have shown a group comprising twohigh voltagecoils with low voltage coils assembled on each side, the specific ar rangemcnt is not essential to my invention and I desire that variations in size, form and arrangement of from the spirit eluded within its scope.

I cl 'm as my invention:

1. n transformer coil raving spaced insular mg strips at sides, insulating channel pieces titted over its edges, angle pieces fitted over the channel pieces, and barrier plates extending along the sides of the coil in convoltage coils which are prei- I parts which do not depart oi my invention shall be ni- I tact with said strips and angle pieces to form an inclosing casing.

2. In an alternating electric current'transformer, the combination with a plurality of coils, of means for insulatin" said coils comprising spaced strips along tIieir'sides, channe pieces fitting over the edges of the several coils, angle and the channel pieces, and barrier plates between the 3. In an alternating electric current transformer, the combination with a plurality of coi s,-of insulating means for said coils comnor plates between adjacent using a plurality ofchannel-pieces which t over the edges of the coils, a series of barsides of the coils,

angle pieces fitting over the channel pieces, and spacing strips between the sides of the coils and the barrier plates.

1 *1. In an alternating electric current transformer, the combination with a plurality of coils, of insulating means for said coils comprising a plurality of channel pieces fitted over the coil edges, barrier plates between adjacent sides of the coils, angle pieces fitted over the channel pieces and spacing strips, all constructed of relatively hard insulating material and constituting a ventilated inclosing casing for said coils.

5. In an alternating electric current transformer, the combination with a coils, of insulating means for said coils com prising channel pieces around arrier plates between the sides of the adjacent coils, angle pieces fitted over the channel pieces, and spacing strips between the coils and the barrier plates.

1 6. In an alternating electric current transformer, the combination with a plurality of coils, of transformer coil insulation comprising a plurality of channel pieces fitting over t is coil edges, angle pieces that overlap each i other around the channel pieces, and barrier lates of hard insulating material which comine with said channc constitute an inclosing and add rigidity thereto.

7'. In an alternating electric current transformer, the combination with a plurality of coils, of means for insulating and supportin i aid coils comprising a plurality of channe l pieces fitting over the coil edges, angle pieces overlapping each other and the channel and angle pieces to casing for the coil ieccs, and barrier plates which are constructed of hard insulating material and the edges of which overlap those of the angle pieces.

8. I 11 an alternating electric current transformer, the combination with a plurality of l coils, of insulating and supporting means for i said coils comprising a plurality of channel pieces which lit over the edges of the coils, a series of barrier plates between adjacent sides of the coils, angle pieces overlapping each other, and spacing strips between the coils and the barrier lates, all of said parts being separating strips constructed of ard insulating material to constitute a ventilated inclosing casing.

9. In an alternating electric currenttransformer, the combination with a plurality of coils, of insulating and supporting means for said coils comprising channel pieces fitted over the coil edges, angle pieces fitted over the channel pieces and having overlapping adjacent edges, barrier plates extending along the sides of the coils and over the ed es of the angle pieces, and spacing strips e- "tween the barrier plates and the coils, all

combini to constitute avventilated, telescopic inc osing casing.

10. A ventilated inclosing and insulating casing for a plurality of coils comprising channel ieces fitted over the edges of each coil, ang e pieces fitted over a plurality of channel ieces and overlapping each other, barrier p ates between the coils the edges of which overlap the strips between the sides;

11. An insulation comprising a pluralitv of barrienplates of hard insulatmgmaterial,

barrier plates and t e co angle pieces, and s acin located at intervals between the plates and insulating fluid around and between the plates.

12. In electric apparatus, the combination with eurrent carrying arts of unlike potcntial, of means for insu ating said parts from each other comprising a wall of insulating fluid maintained between the partsin which barrier-plates of hard insulating material are interposed at regular intervals.

13. In electric apparatus, the combination with current-carrying parts of unlike poten tial, of means for insulating said parts from each other comprising a wall of insulating fluid maintained between the parts in which barrier-plates of hard insulating material are interposed at regular intervals and separated by strips of similar material.

In testimony whereof, I have hereunto subscribed my namethis 12th day of December, 1905.

JESSE E. MATEER.

Witnesses: j

DEAN HARVEY, BIRNEY HINES. 

